12 51 100 Replacing wiring harness section for ignition coils (M54)

Necessary preliminary tasks:

• Read out fault memory of DME control unit.
• Switch off ignition.
• Disconnect battery negative lead from battery.

  Follow instructions for Disconnecting And Connecting Battery  .

• Remove engine cover.
• Remove lower section of microfilter housing on right. See CABIN AIR FILTER .

Unfasten screws.

Remove electronics box cover (1).

Installation:

Engage electronics box cover (1) correctly in hinges.

Fig 1: Engaging Electronics Box Cover

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Unlock plug (1) and detach from DME control unit.

Lift wiring harness with profile seals (2) out of partition or electronics box.

Installation: 

To prevent leaks, you must install profile seals (2) correctly.

Unlock and disconnect plug (3).

Fig 2: Unlocking Plug And Detaching From DME Control Unit

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Detach grounding strap (2) of cable duct from connecting plates (1) of ignition coils.

Fig 3: Detaching Grounding Strap Of Cable Duct From Connecting Plates Of Ignition Coils

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Unlock plug (1) and detach from ignition coils.

Unlock cable strip (2) and remove towards top.

Fig 4: Unlocking Plug And Detaching From Ignition Coils

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Check stored fault messages.

Rectify faults.

Then clear fault memory.